This invention relates to a titanium trichloride catalytic component of high activity advantageously usable in the manufacture of a highly stereospecific .alpha.-olefin polymer and also relates to a method for homo- or co-polymerization of an .alpha.-olefin which is carried out in the presence of this catalytic component and an organo-aluminum compound to obtain a highly stereo-specific polymer.
More specifically stated, this invention relates to an .alpha.-olefin polymerizing titanium trichloride catalytic component obtained in such a manner that, in having a titanium trichloride catalytic component separated from a solution prepared by dissolving titanium tetrachloride, an organic ether compound and an organo-aluminum compound in a solvent, the solvent is a mixed solvent which is prepared by allowing 20 to 70% by volume of an aromatic hydrocarbon halide to be concomitant in a mixed solvent consisting of a saturated aliphatic hydrocarbon and/or an alicyclic hydrocarbon; the organo-aluminum compound, the titanium tetrachloride and the organic ether compound are added to the mixed solvent at a solvent temperature not exceeding 55.degree. C.; following this adding, on the way of a process for raising the solvent temperature to 45.degree.-150.degree. C. a temporary cooling process was repeated twice or more than twice, in the cooling process of which the solvent is temporarily cooled to a temperature lower than 40.degree. C. when the temperature thereof reaches 45.degree.-80.degree. C. and at the time of this cooling the organic ether compound and/or the titanium tetrachloride is further added, thus to have an .alpha.-olefin polymerizing titanium catalytic component of average particle diameter 10 to 1000.mu. separated out, and also relates to a method for homo- or co-polymerization of .alpha.-olefin which is carried out in the presence of a catalyst system comprising this titanium trichloride catalytic component and an organo-aluminum compound.
An important feature of the invention lies in that the average particle diameter of the titanium trichloride catalystic component which is separated out in accordance with this invention is adjustable within a wide range from 10 to 1000.mu. as desired and that the catalytic component thus obtained has highly uniform particle diameter and is highly active when it is used for the polymerization of .alpha.-olefin. In addition to these advantages, a polymer of extremetly uniform particle diameter can be obtained by carrying out homo- or co-polymerization of .alpha.-olefin with a catalyst system which is prepared using this catalytic component in combination with an organo-aluminum compound; and, in accordance with the invented method, the deashing process and the washing process which are normally considered indispensable for the manufacture of an olefin polymer can be either omitted or simplified. Further, in accordance with this invention, a pelletizing process also can be omitted.